(a) Field of the Invention
The present invention relates to electric connectors and, more particularly, to such an electric connector that can be positively soldered to a circuit board.
(b) Description of the Prior Art
According to conventional BGA type electric connectors, the connection between the terminals and the solder balls can be achieved through either of two ways, namely, the pre-soldering -method and the clamping method. The clamping method is easy and inexpensive to apply because it eliminates a pre-soldering process. However, the clamping method may cause a siphon effect, resulting instable bonding. FIGS. 1˜3 show an electric connector constructed according to the aforesaid clamping method. As illustrated, the electric connector 1 is comprised of an electrically insulative housing 3 having a plurality of terminal slots 2, a plurality of terminals 4 respectively mounted in the terminal slots 2 of the housing 3, and a plurality of solder balls 5 located on the bottom side of the housing 3 and respectively connected to the terminals 4 for soldering to a circuit board 7. The terminals 4 are respectively made of a metal plate stamped into a substantially U-shaped profile, each having two bonding ends 6 respectively clamped on the, corresponding solder ball 5. This design of electric connector has drawbacks. One drawback of this design of electric connector is that the solder balls are not aligned in a line when respectively clamped by the bonding ends of the terminals in the terminal slots, affecting the bonding stability of the terminals to the circuit board. Another drawback of this design of electric connector is that a siphon effect will be produced when soldering the solder balls to the circuit board, thereby causing a part of the molten solder to be sucked into the inside of the terminal slots. When cooled down after bonding, some bonding ends of the terminals may not be positively secured to the circuit board.